The invention relates to an industrial linear motor having relatively high output power among linear motors.
A voice coil type of linear motor is used for linear actuators, which are used for moving a magnetic head and an optical pickup and the like in information storage devices. Many of these linear motors are of a movable coil type.
One example of the conventional voice coil-type linear motors is shown in FIG. 15.
A cylinder-shaped outside yoke 101 of which one side end is open configures a fixed side, and a radially magnetized magnet 102 is provided in the inside of the outside yoke 101, and a cylinder-shaped inside yoke 103 is supported so as to be able to coaxially slide with respect to the outside yoke 101 in the direction of an arrow J. The inside yoke 103 is supported by a guide roller 106 with respect to a guide 105 so that a gap between the magnet 102 and a coil 104 may be held uniform.
When electric current is fed through the coil 104, the inside yoke 103 moves in the direction of the arrow J with respect to the outside yoke 101 in accordance with Fleming""s left hand rule based on the direction of the current flowing through the coil 104 and the direction of a magnetic flux xcfx86 of the magnets 102 inter-linking with the current.
However, the above conventional configuration is suitable for use in applications needing small thrust such as information storage devices. However, when used for industrial applications requiring large thrust, may be poor in volume efficiency or problematic in magnetic efficiency.
Concretely, in the conventional configuration, the configuration of the magnetic circuit requires the outside yoke 101 to coaxially cover the whole inside yoke 103, thus resulting in small thrust per unit volume and heavy weight.
Also, it requires an open side end portion of the outside yoke or a slit provided in the outside yoke to permit free motion of the coil.
The invention has an object to provide a linear motor that, despite a voice coil-type linear motor, permits such relatively high output power, small size and light weight, high thrust, and high efficiency as to be available as an industrial linear motor.
A linear motor according claim 1 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that each of the voice coil-type linear motor units comprises an outside yoke having a cylindrical hollow portion, an inside yoke passing through the hollow portion of the outside yoke, a coil wound around the inside yoke along the axial direction thereof, and a magnet mounted to the inside of the hollow portion of the outside yoke and magnetized to a single pole in the surface facing the coil, wherein the ends of the inside yoke are coupled to an adjacent one of the voice coil-type linear motor units by means of auxiliary yokes, the outside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the inner peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by the inside yokes adjacent to each other, the auxiliary yokes, the outside yokes, and the magnets, whereby, by feeding current through the coils of the voice coil-type linear motor units adjacent to each other, the outside yokes and the inside yokes are effected to move relative to each other based on magnetic action of a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim 2 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that each of the voice coil-type linear motor units comprises an outside yoke, having a cylindrical hollow portion, an inside yoke, passing through the hollow portion of the outside yoke, a coil mounted to the inside of the hollow portion of the outside yoke and wound along the axial direction of the inside yoke, and a magnet mounted to the inside yoke and magnetized to a single pole in the surface facing the coil, wherein the ends of the inside yoke are coupled to another adjacent above-described voice coil-type linear motor unit by mean of auxiliary yokes, the inside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the outer peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by the inside yokes adjacent to each other, the auxiliary yokes, the outside yokes, and the magnets, and thereby, by feeding current through the coils of the voice coil-type linear motor units adjacent to each other, the outside yokes and the inside yokes are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim 3 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, coils separately wound in a plurality of sections around the inside yokes along the respective axial directions thereof, and outside yokes having cylindrical hollow portions, into which the inside yokes are inserted, and provided with magnets on the insides of the hollow portions correspondingly to the coils separately wound in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils, and the outside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the inner peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by a plurality of the outside yokes, the inside yokes, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
A linear motor according to claim 4 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, magnets separately provided in a plurality of sections on the inside yokes along the respective axial directions thereof, and outside yokes having cylindrical hollow portions, into which the inside yokes are inserted, and having coils wound on the insides of the hollow portions correspondingly to the magnets separately provided in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils and are configured such that the magnets of the voice coil-type linear motor units adjacent to each other may be of different magnetic poles, and thus a closed magnetic path is formed by the outside yokes, the inside yoke, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
A linear motor according to claim 5 of the invention is characterized in that it comprises a movable unit comprising an outside yoke having a cylindrical hollow portion and an annular magnet fixed so as to cover nearly all surface of the inner peripheral surface of the hollow portion, and a fixed unit comprising a column-shaped inside yoke and a coil wound around an outer periphery portion thereof, wherein a plurality of pairs of each of the movable unit and the fixed unit are arranged side by side, opposite ends of the plurality of the fixed units are coupled by individual auxiliary yokes, and the outside yokes are face-joined to each other such that the inner peripheral surfaces of the magnets of the movable units adjacent to each other may be of different magnetic poles, and guide mechanisms for holding nearly uniform gaps between the outer periphery portions of the coils and the inner peripheral surfaces of the magnets are provided between the sides of the auxiliary yokes and the outside yokes.
A linear motor according to claim 6 of the invention is characterized in that it comprises a movable unit comprising an outside yoke having a cylindrical hollow portion and an annular magnet fixed so as to cover nearly all surface of the inner peripheral surface of the hollow portion, and a fixed unit comprising a column-shaped inside yoke and coils separately wound in two sections around the outer periphery portion of the inside yoke, wherein the fixed units are arranged side by side, four movable units are mounted to face the coils of four sections such that the inner peripheral surfaces of the magnets adjacent to each other may be of different magnetic poles, and opposite ends of the fixed units are coupled by coupling blocks, the outside yokes of two sets of the movable units arranged side by side are face-joined to each other, and the linear motor further comprises holding means for coupling the two face-joined movable units to hold a constant spacing of one movable stroke between them, and guide mechanism, provided between the side of the coupling block and the outside yokes, for holding nearly uniform gaps between the outer periphery portions of the coils and the inner peripheral surfaces of the magnets.
A linear motor according to claim 7 of the invention is characterized in that it comprises a fixed unit comprising an outside yoke having a cylindrical hollow portion and an annular magnet fixed so as to cover nearly all surface of the inner peripheral surface of the hollow portion, and a movable unit comprising a column-shaped inside yoke and coils wound around the outer periphery portion thereof, wherein a plurality of pairs of each of the movable unit and the fixed unit are arranged side by side, opposite ends of the plurality of the movable units are coupled by individual auxiliary yokes, and the outside yokes are face-joined to each other such that the inner peripheral surfaces of the magnets of the fixed units adjacent to each other may be of different magnetic poles, and guide mechanisms for holding nearly uniform gaps between the outer periphery portions of the coils and the inner peripheral surfaces of the magnets are provided between the side of the auxiliary yokes and the outside yokes.
A linear motor according to claim 8 of the invention is characterized in that it comprises a fixed unit comprising an outside yoke having a cylindrical hollow portion and an annular magnet fixed so as to cover nearly all surface of the inner peripheral surface of the hollow portion, and a movable unit comprising a column-shaped inside yoke and coils wound separately in two sections around the outer periphery portion of the inside yoke, wherein the movable units are arranged side by side, four fixed units are mounted to face the coils of four sections such that the inner peripheral surfaces of the magnets adjacent to each other may be of different magnetic poles, opposite ends of the movable units are coupled by coupling blocks, and the outside yokes of two sets of the fixed units arranged side by side are face-joined to each other, and the linear motor further comprises holding means for coupling between two face-joined movable units to hold a constant spacing of one movable stroke between them, and guide mechanisms, provided between the sides of the coupling blocks and the outside yokes, for holding nearly uniform gaps between the outer periphery portions of the coils and the inner peripheral surfaces of the magnets.
A linear motor according to claim 9 of the invention is characterized in that, in any one of claims 5 to 8, the magnets are divided into a plurality of parts to be fixed on the inner peripheral surface of the hollow portion.
A linear motor according to claim 10 of the invention is characterized in that, in any one of claims 5 to 8, the magnet is shaped like a plate, and the inside yoke is shaped like a hexagonal or octagonal prism.
A linear motor according to claim 11 of the invention is characterized in that, in any one of claims 5 to 8, the outside yoke is configured as a lamination of electrical sheets.
A linear motor according to claim 12 of the invention is characterized in that, in any one of claims 5 to 8, the outside yoke is divided into two parts along the radial direction.
A linear motor according to claim 13 of the invention is characterized in that it comprises an outside yoke having a plurality of cylindrical hollow portions extending side by side with each other, a plurality of column-shaped inside yokes passing through the hollow portions of the outside yoke, coil wound around the inside yokes along the axial directions thereof, and magnets mounted to the insides of the hollow portions of the outside yoke and-magnetized to a single pole in the surfaces facing to the coils, wherein the opposite ends of the inside yokes are coupled by auxiliary yokes, the magnets provided in the hollow portions adjacent to each other are arranged such that the inner peripheral surfaces of the magnets may be of different magnetic poles, thus forming a closed magnetic path by the inside yokes, the auxiliary yokes, the outside yoke, and the magnets, and thereby, by feeding current through the coils, the outside yoke and the inside yokes are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim 14 of the invention is characterized in that it comprises an outside yoke having a plurality of cylindrical hollow portions extending side by side with each other, inside yokes passing through the hollow portions of the outside yoke, coils mounted to the insides of the hollow portions of the outside yoke and wound along the axial direction of the inside yokes, and magnets mounted to the inside yokes and magnetized to a single pole in the surfaces facing to the coils, wherein the opposite ends of the inside yokes are coupled by auxiliary yokes, the inside yokes adjacent to each other are configured such that the outer peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by the yokes adjacent to each other, the auxiliary yokes, the outside yoke, and the magnets, and thereby, by feeding current through the coils, the outside yoke and the inside yokes are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and the coils.
A linear motor according to claim 15 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, coils separately wound in a plurality of sections around the inside yokes along the respective axial directions thereof, and outside yokes having a plurality of cylindrical hollow portions extending side by side with each other and into which the inside yokes are inserted, and having magnets provided on the inside of the hollow portions correspondingly to the coils separately wound in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils, and the outside yokes of the voice coil-type linear motor units adjacent to each other are configured such that the inner peripheral surfaces of the magnets may be of different magnetic poles, and thus a closed magnetic path is formed by a plurality of the outside yokes, the inside yoke, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
A linear motor according to claim 16 of the invention is configured with a plurality of voice coil-type linear motor units arranged in parallel to each other, characterized in that it comprises inside yokes arranged side by side, magnets separately provided in a plurality of sections on the inside yokes along the axial directions thereof, and outside yokes having cylindrical hollow portions into which the inside yokes are inserted, and having coils wound on the insides of the hollow portions correspondingly to the magnets separately provided in the plurality of sections, wherein the magnets are magnetized to a single pole in the surfaces facing the coils, and are configured such that the magnets of the voice coil-type linear motor units adjacent to each other may be of magnetic poles different from each other, and thus a closed magnetic path is formed by the outside yokes, the inside yokes, and the magnets, and thereby, by feeding current through the coils, the outside yokes coupled and the inside yokes coupled are effected to move relative to each other based on magnetic action caused to occur between a magnetic field generated by the closed magnetic path and a magnetic field generated by the coils.
An X-Y table according to claim 17 of the invention is characterized by equipping the linear motor according to any one of claims 1 to 8, and claims 13 to 16.